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Spies Hecker GmbHHorbeller Str. 17D-50858 KölnTel.: +49 (0) 2234 6019 4050Fax: +49 (0) 2234 6019 4100www.spieshecker.com
Diagnosing paint defectsMercedes-Benz PC & CV.
Spies Hecker – simply closer.
The examples and suggestions in this booklet are intended tohelp you prevent paint defects, identify environmental effectsand produce nothing but immaculate paint finishes.
We wish you continued success!
Diagnosing paint defectsMercedes-Benz PC & CV.
Identifying and remedying paint defects and environmental effects.
Spies Hecker hopes that this collection of the most frequentpaint defects will serve the practitioner as a handy referencesource in his daily work.
Only by correctly assessing defects is it possible to eliminate thecauses and effectively remedy the damage to the painted surface.In addition, paintwork may also be damaged by a whole range ofenvironmental effects, which have to be identified and remedied.
Despite careful preparation, advanced application methods andthe use of high-grade paint systems, flaws in a vehicle refinish can never be entirely excluded. However, a quality paintshop todaycannot afford to produce flawed paintwork.
Eliminating a defect is often troublesome and time-consuming.What are the causes? What mistakes have been made? How can such mistakes be avoided in future?
Paint defects
10 Poor opacity.
12 Dirt inclusions.
14 Orange peel / poor flow.
16 Holograms.
18 Color separation on sealant.
20 Runs.
22 Clouding or mottling in metallic finishes.
24 Solvent popping.
26 Edge mapping.
28 Polyester bleeding.
30 Water spotting.
32 Sanding marks.
34 Moisture blistering.
36 Lifting / wrinkling.
38 Pinholes.
40 Matting.
42 Salt and pepper effect.
44 Dirt and dust in the base coat.
46 Dirt and dust in the clear coat.
48 Poor adhesion.
50 Adhesion problems between base coat and clear coat.
52 Halo effect in blending areas.
Contents.Environmental effects
56 Bird droppings.
58 Acid rain.
60 Stone chipping.
62 Tree sap.
64 Bug marks.
66 Tar.
68 Industrial fallout.
70 Splashes of lime or cement.
72 Corrosion.
74 Car wash scratches.
76 Color fade / change.
Miscellaneous
80 Plastic film marks.
82 Transport damage.
Paint defects.
Paint defects
10 11
Cause
Insufficient top coat applied.
Incorrectly produced, uneven substrate (effect finishes).
Prevention
Keep to the film thicknesses specified on the Technical Data Sheets.
For low-opacity colors, use the specified surfacer.
Spray a neutral-colored substrate.
Remedy
Sand the surface and respray.
Poor opacity.
Definition
Uneven coloration.
Substrate visible through top coat.
Paint defects
12 13
Cause
Surface not carefully cleaned.
Faulty ceiling filters.
Pressure in the spray booth too low.
Unsuitable work clothes.
Dirty spray booth.
Prevention
Carefully blow off the surface, clean it and then wipe with a tack cloth.
Check filters regularly.
Wear lint-free overalls.
Maintain spray booth regularly.
Remedy
Sand defect lightly and polish.
Sand and respray large surfaces.
Dirt inclusions.
Definition
Particles projecting through the top coat.
Paint defects
14 15
Cause
Paint viscosity too high.
Fast, highly volatile reducers.
Incorrect nozzle size.
Spray gun too far from object; not enough paint applied.
Prevention
Set the right spray booth temperature.
Adapt the paint system to the repair job and spray booth temperature.
Set the right paint viscosity with a DIN viscosity cup.
Check and maintain spraying distance (follow spray gun manufacturer’s recommendations).
Remedy
On small surfaces, sanding and polishing are possible.
On large surfaces, sand down the texture and respray.
Orange peel / poor flow.
Definition
Surface texture resembling orange peel.
Paint defects
16 17
Holograms.
Definition
3D effect on dark paint surfaces on which a paint defect has been remedied.
Mostly elliptical or circular clouding; greyish iridescence like that of an oil film.
Cause
Remedying of defects and dust nibs on mostly dark top coats or clear coats.
Prevention
Use products specified by polish manufacturer.
Use suitable sanding materials.
Keep to the drying times for the paint systems employed.Follow instructions on the Technical Data Sheets.
Remedy
Treat surface again with suitable polishes.
Paint defects
18 19
Color separation on sealant.
Definition
Sealant visible through top coat.
Cause
Sealant overpainted too soon.
Insufficient wetting of top coat on sealant.
Prevention
Allow enough time for sealant to dry.
Apply a thin initial coat of base / top coat over seals.
Remedy
Respray.
Paint defects
20 21
Cause
Uneven paint application.
Specified spray viscosity not observed.
Unsuitable reducers.
Material or spray booth temperature too low.
Film thicknesses too high.
Faulty spray gun (nozzle).
Flash-off between coats too short.
Prevention
Comply with instructions on object, paint and spray booth temperature.
Check spraying equipment regularly.
Mix and apply paint in accordance with the instructions on the Technical Data Sheets.
Remedy
After the specified drying time, flat any runs. If necessary, use an infrared heater for further drying and then polish.
If the runs have been sanded right through, respray.
Runs.
Definition
Paint runs on vertical body parts.
Paint defects
22 23
Cause
Faulty spray gun (nozzle).
Incorrect air pressure, unsuitable reducer, unsuitable spraying technique, unsuitable spray viscosity.
Prevention
Use mixing stick or DIN viscosity cup to obtain spray viscosity.
Maintain spray guns regularly.
Hold spray gun parallel to object while spraying (observe correct distance). Follow the spray gun manufacturer’s instructions.
Follow the application recommendations on the Technical Data Sheets.
Remedy
Allow clear coat to dry thoroughly, then sand the surface and respray.
Clouding or mottling in metallic finishes.
Definition
Uneven color / effect.
Paint defects
24 25
Cause
Excessive film thickness.
Top coat not allowed to flash off long enough before forced drying.
Specified spray viscosity not observed.
Unsuitable hardener or reducer.
Prevention
Apply paint in normal film thicknesses.
Keep to specified flash-off times.
Follow the instructions on spray viscosity, hardeners and reducers on the Technical Data Sheets.
Remedy
Sand the affected areas lightly with a sanding pad and respray within 24 hours. Do not sand pop marks open.
Where there are large bubbles / pop marks, sand down the surface completely and reapply the paint system.
Solvent popping.
Definition
Small bubbles in the top coat, some of them burst.
Paint defects
26 27
Cause
Old paintwork not sanded down smoothly at the edges.
Putty and surfacer applied on top of elastic factory finish.
Surfacer sanded and recoated before it had fully dried.
Substrate not completely dry.
Priming material applied in excessive film thickness and not allowed to dry properly.
Prevention
Carry out a solvent test on the substrate (elastic / hard).
Apply putty to bare metal only.
On elastic substrates apply surfacer to complete panels.
Remedy
After the top coat has fully dried, fine-sand and polish.
Sand, isolate with a surfacer and spray again.
Edge mapping.
Definition
Edges showing through in the top coat.
Paint defects
28 29
Cause
Too much hardener in the polyester putty.
Prevention
Isolate areas of putty with suitable materials.
If necessary, use putty dispenser.
Avoid using excessive hardener in the putty.
Remedy
If too much hardener was used in polyester putty, sand off polyester putty and repeat application using correct putty / hardener ratio.
Polyester bleeding.
Definition
Discolored patches in metallic finishes.
Paint defects
30 31
Cause
Warm, not fully hardened top coat spotted with water droplets, usually immediately after oven drying.
Prevention
Observe drying time.
Allow object to cool after oven drying.
Remedy
Lightly sand and polish.
Sand damaged area and respray.
Water spotting.
Definition
Marks and raised edges of water droplets on fresh finishes.
Paint defects
32 33
Cause
Excessively coarse sanding materials for substrate preparation.
Prevention
Sand putty with P 120-180 (initial sanding) and P 240-320 (final sanding).
Surfacer: dry P 400-500, wet P 800-1200.
Follow instructions for substrate preparation on the Technical Data Sheets.
Remedy
When the top coat has fully dried, fine-sand and polish the paint surface.
To eliminate serious damage, sand paint surface and respray.
Sanding marks.
Definition
Sanding marks with swollen edges.
Paint defects
34 35
Cause
Moisture absorbed by the substrate.
Insufficient substrate drying after wet sanding (particularly a problem with polyester products).
Condensation due to temperature fluctuations.
Polyester products not isolated.
Damp compressed air.
Prevention
Dry-sand and isolate polyester products.
Ensure that the supplied compressed air is clean.
Remedy
Sand down the affected area completely, matt-sand the unaffected remaining surface, clean with silicone remover, apply surfacer and then respray.
Moisture blistering.
Definition
Small raised pimples appearing in the paint film.
Paint defects
36 37
Cause
Substrate solvent-sensitive or not fully cured.
Areas where clear coat was sanded through to base coat either not isolated or isolated with an unsuitable surfacer.
Unsuitable substrate (e.g. aerosol-can finish with TPA or nitrocellulose paints).
Unsuitable priming materials, top coats or reducers.
Prevention
Carry out a solvent test on problem substrates.
Apply several thin coats of a 2K surfacer to problem substrates and allow longer flash-off.
Remedy
Completely remove the fully dried area of wrinkled top coat together with the affected substrate and apply the paint system again.
Before applying the top coat, lightly sand the entire area.
Lifting / wrinkling.
Definition
Lifting / wrinkling of the paint surface.
Paint defects
38 39
Cause
Air trapped in putty.
Excessive putty film thickness.
Incorrect spray viscosity for surfacer materials.
Excessive surfacer film thickness.
Insufficient flash-off between coats.
Prevention
Follow the application recommendations on the Technical Data Sheets.
Choose the right hardener for the temperature.
Observe flash-off times.
Remedy
Sand down pinholes, apply surfacer if necessary and reapply paint system.
Pinholes.
Definition
Small, pinhole-like depressions.
Paint defects
40 41
Cause
Surfacer not allowed to dry properly.
Unsuitable reducers or hardeners.
Hardener had already reacted with moisture.
Poor air circulation in drying oven.
Extraordinary climatic conditions.
Film thickness too high or low.
Prevention
Keep to the • drying times and• film thicknesses specified on the Technical Data Sheets.
Use only the recommended reducers.
Close hardener cans immediately after use.
Check air circulation in drying oven.
Remedy
After drying, polish the affected area to a full gloss or, alternatively, lightly sand the whole surface, clean with silicone remover and respray.
Matting.
Definition
Loss of top coat gloss.
Paint defects
42 43
Salt and pepper effect.
Definition
Black and white stippling / impurities in the base coat.
Cause
Material insufficiently filtered.
Incorrect storage temperature (waterborne base coat).
Material past end of shelf life.
Insufficiently stirred base coat.
Prevention
Use a suitable strainer.
Observe storage temperature (as given on the Technical Data Sheets).
Stir the tinters in the mixing machine regularly.
Remedy
Sand and respray with uncontaminated material.
Paint defects
44 45
Dirt and dust in the base coat.
Definition
Dirt particles projecting from the base coat.
Cause
Base coat not filtered.
Incorrect cleaning of the surface (dirt from rebates, etc.).
Dirt from clothing (refinisher).
Unsuitable tack cloth / dirty spray booth and filters (ceiling, floor).
Prevention
Filter base coat.
Clean surface correctly (including rebates, etc.).
Wear clean overalls.
Use suitable tack cloth.
Maintain the spray booth regularly.
Remedy
Clean with silicone remover, tack cloth (sand if necessary) and reapply base coat.
Paint defects
46 47
Dirt and dust in the clear coat.
Definition
Dirt particles projecting from the clear coat.
Cause
Clear coat not adequately filtered.
Incorrect cleaning of the surface (dirt from rebates, etc.).
Dirt from clothing (refinisher).
Dirty spray booth and filters.
Prevention
Filter clear coat well.
Clean surface correctly (including rebates, etc.).
Wear clean overalls.
Maintain the spray booth regularly.
Remedy
Sand (P 1500) and polish.
If exceptionally contaminated, sand and then respray base coat and clear coat.
Paint defects
48 49
Poor adhesion.
Definition
Loss of putty adhesion on bare metal (steel, zinc or aluminum).
Cause
Unsuitable substrate.
Putty overheating during IR drying.
Insufficient substrate preparation.
Prevention
Choose suitable putty for the substrate.
Observe distance from heater.
Choose correct preparation.
Remedy
Sand down and start again.
Paint defects
50 51
Adhesion problems betweenbase coat and clear coat.
Definition
Poor adhesion between base coat and clear coat.
Clear coat peels off.
Cause
Insufficient flash-off before clear coat application.
Base coat film too thick.
Prevention
Observe flash-off times (follow instructions on the Technical Data Sheets).
Observe film thicknesses (follow instructions on the Technical Data Sheets).
Remedy
Sand and respray.
Paint defects
52 53
Halo effect in blending areas.
Definition
Visible edge when blending in from the base coat.
Cause
Edge zone sprayed too dry / wet.
Incorrect spraying technique.
Spraying pressure too high.
Spray booth temperature too high.
No blend-in additive used.
Prevention
Check spray booth temperature.
Use blend-in additive in accordance with instructions on the Technical Data Sheets.
Remedy
Sand clear coat, and respray base coat and clear coat.
Environmental effects.
Environmental effects
56 57
Cause
The different types of food ingested by birds affect the composition and quantity of droppings.
Chemical aggression on the paint surface may be caused by strong organic acids acting for an extended period and exposed to high temperatures.
Remedy
Depending on the type of damage, the remedy ranges from polishing to a complete respray.
Bird droppings.
Definition
The damage can range from paint discoloration to the film dissolving completely.
Bubbling, swelling and etching are typical phenomena.
Environmental effects
58 59
Cause
Etching of the paint surface by acid rain.
Destruction of the paint film by the sulphurous acid or even sulphuric acid contained in acid rain.
Remedy
Repair paint surface by polishing.
In the event of severe damage, a respray may be necessary.
Acid rain.
Definition
Droplet-like spots with sunken edges or edge zones.
Environmental effects
60 61
Cause
Serious mechanical stressing of the paint surface, particularly at the front of the vehicle.
Small stones or chippings thrown up at the paintwork by other vehicles.
Remedy
Local repair is possible with a brush.
If stone chipping is widespread, sand and replace paint system.
Stone chipping.
Definition
Dot-like, angular or crater-like damage to the paint.
Tiny impact holes in the paint surface.
Environmental effects
62 63
Cause
Chemical aggression from tree sap and blossom resin.
Remedy
Remove tree sap carefully, so as not to damage the top coat.
Allow cloths soaked in silicone remover to act for some time, then carefully scrape off the tree sap with a plastic spatula.
Polish (if necessary sand and polish).
Respray if damage is serious.
Tree sap.
Definition
Thread or droplet-like deposits then can etch deep into the paintwork.
Environmental effects
64 65
Cause
Insect secretions reacting on exposure to moisture and heat.
Substances allowed to act for a long time.
Remedy
Clean with water or silicone or tar remover.
Polish (if necessary sand and polish).
If the damage cannot be remedied by polishing, respray.
Bug marks.
Definition
Etching of the top coat.
Damage can range from loss of gloss to the complete dissolving of the top coat down to the surfacer.
Environmental effects
66 67
Cause
Spots of tar diffusing into the paint film.
Made worse by lack of care.
Remedy
Immediately remove with tar remover or silicone remover and then polish.
If allowed to act for too long, respraying is the only remedy.
Tar.
Definition
Dark or yellow dot-like marks surrounded by a halo of discoloration.
Environmental effects
68 69
Cause
Chemical destruction of the paint film by the corrosion of individual rust particles on the paint film.
Remedy
Depending on the extent of the chemical reaction, polish (or sand and polish).
Chemical remedy possible (please contact our Technical Service).
Respray in the event of serious damage.
Industrial fallout.
Definition
Particles of rust locally visible on the top coat.
Environmental effects
70 71
Cause
Chemical destruction of the paint film by splashes of lime or cement.
Remedy
Depending on the extent of the damage, polish (or sand and polish).
Respray if polishing does not help.
Splashes of lime or cement.
Definition
Matted surfaces with bright, whitish marks.
Etched areas on the paint surface.
Environmental effects
72 73
Cause
Stone chipping in conjunction with de-icing salt and moisture.
Penetration of moisture into the damaged paint film.
Bare metal exposed to moisture before priming.
Inadequate vehicle care.
Prevention
Before priming, thoroughly clean and degrease the bare metal.
Remedy
Remove rust from areas of corrosion by sand-blasting, with wire brushes or with CSD cleaning discs.
If the rust is serious, part replacement may be advisable.
Complete new respray.
Corrosion.
Definition
Mechanical damage with rust beneath the paint film.
Environmental effects
74 75
Cause
No or insufficient prewash.
Washing with too little water.
Wash brushes worn or dirty.
Remedy
Mechanical polishing.
Sealing the paint surface with hard wax.
Proper car care.
Car wash scratches.
Definition
Uniform and almost parallel scuff and scratch marks of varying depth.
Dull paint surfaces.
Environmental effects
76 77
Cause
Destruction of the paint pigment by UV radiation and weathering.
Remedy
Respray.
Recommended is a solid-color 2-coat system.
Color fade / change.
Definition
White, light-colored, pale surfaces, mostly horizontal.
Staining with discolored spots.
Miscellaneous.
Miscellaneous
80 81
Cause
Plastic film placed too soon over paintwork that was not completely dry.
Prevention
Vapor-diffusing film should be used.
Follow the instructions of the plastic film manufacturer.
Remedy
Remove remains of adhesive with silicone remover or other mild cleaners.
Then polish.
If necessary, sand surfaces and respray.
Plastic film marks.
Definition
Plastic film contact marks are clearly visible.
Remains of film adhesive.
Miscellaneous
82 83
Transport damage.
Definition
Scratch marks of varying depth.
Cause
Insufficient protection of factory finish during improper transport.
Prevention
Covering the original paintwork (plastic film or protective paint).
Remedy
Sand shallow scratches and polish.
Deeper scratches require a refinish.
Spies Hecker GmbHHorbeller Str. 17D-50858 KölnTel.: +49 (0) 2234 6019 4050Fax: +49 (0) 2234 6019 4100www.spieshecker.com
Diagnosing paint defectsDaimler AG PC & CV.
Spies Hecker – simply closer.
